Since 2011, his name has also been associated with a charity “loop-a-thon” around Connemara.

Mr Mansfield planned to diversify the trademark into other products, including water, soft drinks and alcohol, but was informed that Cooley Distillery had lodged an objection in February 2016.

Likelihood of confusion

The Co Louth distillery, now owned by the US-based Japanese multinational Beam Suntory, has a community trademark for its peated single malt whiskey called Connemara.

In its objection, it argues that its own label has “established goodwill and recognition” and is used extensively in the State and internationally.

It says there is the likelihood of “confusion among consumers, if ‘Conn O’Mara’ is given a trademark, and it would be giving an “unfair advantage” to the detriment of the “distinctive character” of its whiskey.

Mr Mansfield has condemned as “deplorable” a request by Cooley to award costs against his family business if it goes to court, and describes it in his correspondence to the Patents Office as “corporate bullying”.

A spokeswoman for Beam Suntory said it was “confident of its position on this matter”.

The Patents Office said it did not comment on “particular ongoing opposition cases” and said there is no prescribed period in which it must adjudicate in cases of trademark oppositions.

It said that the registration of geographical names as trademarks is “not possible where such a geographical name is either already famous, or is known for the category of goods concerned.

However, geographical names “are not debarred per se from registration as trademarks” and each application must be examined on its own merits.